1. Field of the Invention
The present invention relates to a high productivity, high metal removal rate insert which improves force distribution across the rake face and has a cutting surface which is configured in an arcuate concave, convex configuration.
The present invention further relates to an indexable cutting insert having force distribution which lowers stress concentration at the depth of cut line to minimize notch formation and which is equipped with a raised, central island formed in the upper surface to protect the fastening means from injury by the chips during cutting.
The present invention further relates to a high productivity, high metal removal rate insert which descends bi-directionally from the cutting edge toward the center of the insert. The bi-directional descending surfaces form a stabilizer pad where they intersect at each corner or nose area of the insert to impart improved impact resistance to the nose area of the insert.
The present invention further relates to a high productivity, high metal removal rate insert having a cutting edge shaped in an arcuate concave convex configuration, and further provided with an upper surface whose arcuate concave, convex surface corresponds to the shape of the cutting edge.
2. Description of the related art
Plansee TIZIT GmbH has recently introduced an insert designated as Sr137 TR, which is disclosed in their European sales brochure entitled "TIZIT Starmaster". The insert in question features an arcuate concave, convex upper surface and cutting edge, but the two arcuate surfaces are "out of synch" which each other such that when the cutting edge is concave, the upper surface is convex, and vice versa. Moreover, the Plansee insert does not feature bidiectional descending surfaces from the highest point of the cutting edge, which is located at the nose radius, toward the center of the insert.
The insert of the present application features an arcuate concave convex cutting surface and upper surface which correspond to each other. In other words, when the cutting surface of the insert of the present application is concave, the upper surface is concave, and vice versa. This allows the insert of the present application to exhibit improved force distribution across the rake surface of the insert which reduces localized stress concentrations at depth of cut and further improves impact strength during heavy cutting operations.